In order to evaluate seismic safety of piping systems with locally wall thinning by LDI, hybrid tests have been conducted incorporating a numerical analysis of whole s ystem with a loading test of elbow model. Seismic performance effects of wall thinning elbow were clarified by comparing three cases of different thickness elbow model s such as no defect, 50% thinning and 75% thinning. By these results, the almost same hystereses of the non-linear load displacement relations were obtained and the dam ages o...
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Seismic safety evaluation of piping systems with locally wall thinning by LDI (Part3)-Seismic performance effects of elbow pipes by loading tests

In this study, the new Positive Contrast (PC) method was proposed to emphasize the tumors in MRI images. If the object includes magnetic particles such as S PIO(Super Paramagnetic Iron Oxide), the dark image is obtained because of the MRI's distorted magnetic field by the magnetic particles. This effect appears as the shift of peak position in K-space calculated from the Fourier transform of the sub-area of the MRI images. The tumor-emphasized MRI images were obta ined by selecting only the sub-areas that ...
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Enhancement of Negative Image of MRI by the Positive Contrast Method

ＰＷＲ一次冷却材圧力バウンダリにおける応力腐食割れへの対応について 荒川 嘉孝,Yoshitaka ARAKAWA......

Validation of ultrasonic testing (UT) for detecting stress corrosion cracks (SCCs) in the Pressurizer's dissimilar metal weld of nuclear power plant, PWR, was carried out. Appropriate UT methods using probes consist of separate transmit and receive piezo-electric elements with longitudinal wave can detect both axial and circumferential SCCs ranged from 12% to 23% thickness of weld. ...
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Validation of Ultrasonic Testing for PWR Pressurizer Dissimilar Metal Weld

Eddy Current testing (ECT) for detecting stress corrosion cracks (SCCs) in the vessel's dissimilar metal weld of PWR plants was carried out. Appropriate ECT with a single cross-coil can detect shallow artificial SCCs with depth of 0.5mm or over. And magnetic saturation method is very effective for decreasing noise signals come from permeability change in the boundary region between overlay and buttering of safe-end....
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Development of Eddy Current Testing Method for PWR Vessel’s Dissimilar Metal Weld

Magneto-Acoustic Emission (MAE) is stress pulses observed during dynamic magnetization process of ferromagnetic material, which is caused by abrupt and discontinuous motion of magnetic domain wall pinned by inclusions, voids, dislocations, grain boundaries etc. It is known that the incidence of MAE has significant correlation with the rate of magnetization change, so that the characteristics of MAE depend on the applied stress because of Magneto-Elastic Coupling (MEC). In this paper, we examine the cor...
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Study on Relation between Magnetization Curve and Magneto-Acoustic Emission of SM490A Steel

A circular electromagnetic TE11-mode is used for detection of longitudinal crack in a stainless steel pipe. To show the capability of microwave nondestructive t esting for detection of crack in large and complex piping systems such as steam generator (SG) tube, inspected pipe including U-bend are examined in this study....
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Microwave Nondestructive Detection of Longitudinal Crack in Pipe with U-bend

In Japanese nuclear power plants, ultrasonic testing is performed as in-service inspection for piping welds according to JSME code. W e developed new UT system for piping welds to improve reliability and efficiency. Automated scanning equipments and digital acquisiti on units realized high quality and repeatability of UT data. Analysis system with various automated function and 3D model function rea lized high reliability and high speed of data analysis. In this paper, the outline and advantage of UT analy...
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Advanced UT Evaluation Applying UT Analysis System

X-Ray diffraction spots from coarse grains of austenitic stainless steel, SUS316L, were measured with an area detector. The error of the measurement of the diffraction angle was investigated.“ -method ”was proposed to solve the error due to the position of the coarse grain. However, the -method was not effective in solution of the error. A double-exposure method (DEM) was proposed as the measurement without error due to the position of the coarse grain. The DEM did not solve the error due to the divergen...
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A Study on Strain Measurement of Coarse Grains Using X-Ray Area Detector

More than fifty civil law cases have been filed to prohibit the electric power companies from operating their nuclear plants. Plaintiffs, usually residents near the plants, prevailed so far in seven cases. Written in detail of fact findings and with enormous amount of intellectual energy, those seven court decisions have in common some shortcomings in proper understanding of nuclear power regulations....
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Some Aspects of Judicial Review of Safety of the Nuclear Power Plant